[kbs666]

You have a lot wrong.

A structure only export does not rely on tags.
Tagging is very smart. It uses an existing feature to do something rather than adding an entirely new one. If you designate an export as full it will be full and the export tag will be applied everywhere.

Partial exports do work the same way. The easiest way to apply the export tag is to create the export, but not do the export then create a view of the material you want in that export and use the bulk tagging feature to apply that tag to the entire view. the bulk tagging feature was added for expressly this usage.

Structure exports are not required prior to exporting data. Any export of a realm will also include the structure of the realm.

To the best of my knowledge no one has produced a DTD or XSD of the export file XML. According to what we've been told compact is for consumption by programs not RW while full is for RW's use.